SAN FRANCISCO (CN) - A federal judge Wednesday granted summary judgment to leaders of the International Union of Operating Engineers who were accused of squandering pension funds on bad investments.

In granting summary judgment on the two remaining ERISA claims, U.S. District Judge Edward Chen found there is no question that the claims, whether based on the duty of prudence or duty of loyalty, were time-barred. Chen also denied the plaintiff union members' motion for summary adjudication as moot.

In 2013, lead plaintiff David Slack accused the International Union of Operating Engineers, Local 3 - headquartered in Alameda - and 68 other defendants of violating labor management laws, the California Labor Code, ERISA and federal anti-racketeering law.

The IUOE represents heavy-equipment operators and other construction workers and is the tenth-largest union in the AFL-CIO. Local 3 is its largest branch, representing workers in California, Nevada, Utah, Hawaii and the Pacific Rim islands.

In addition to claiming that the union illegally forced members to contribute 1 percent of their salaries to a political action committee, the plaintiffs said they paid millions to the Hawaiian Stabilization Fund - an alleged multimillion-dollar slush fund for union bosses disguised as a mechanism to keep contractors from operating "double-breasted," and working both union and nonunion jobs.

The plaintiffs who brought the two remaining ERISA claims had participated in the union's pension fund, and accused the fund's trustees of breaching their fiduciary duties to union members by investing $90 million in a risky investment fund called the Longview Fund.

In considering whether the plaintiffs' claims were time-barred, Chen used the six-year statute of limitations to determine if the last breach of fiduciary duty occurred on or after Oct. 27, 2007: the plaintiffs sued on Oct. 27, 2013.

The defendants argued that the last breach occurred no later than Oct. 22, 2007, when the pension fund signed a contract to act as the Longview Fund's investment manager. But the plaintiffs said the breach occurred when the board invested money in the Longview Fund, which was after Oct. 27, 2007.

Chen cited the plaintiffs' allegation that "the pension fund trustees breached their fiduciary duties under ERISA by agreeing to invest $100,000,000 in pension fund monies, and actually investing $90,000,000 without proper due diligence, in the Longview investment," calling it "problematic."

"Plaintiffs focus on the words 'actually investing $90,000,000' but it is the subsequent phrase 'without proper due diligence' that is telling," Chen wrote. "The failure to do due diligence was in conjunction with the investigation of AB [Amalgamated Bank, the investment manager] and the Longview Fund; this alleged failure took place prior to the decision to enter into the IMA [investment management agreement] with AB on October 22, 2007."

Chen then turned to the plaintiffs' definition of a fiduciary act as the formal investment of money. The plaintiffs argued that the pension fund was not legally obligated to invest in the Longview Fund. In fact, the pension fund never made an investment, and did not breach its fiduciary duty until it transferred money to Longview's investment manager, the plaintiffs said.

But Chen noted that the investment management agreement states that the pension fund had "committed" to invest in the investment fund, and that the term "committed" implies a legal obligation.

"Accordingly, the Court concludes that, in spite of plaintiffs' attempt to characterize the breach as the actual transfer of money to AB, the 'true' breach was defendants' decision to approve, without exercising the requisite due diligence of a prudent investigation, the Longview investment and relationship with AB in the first place, which was consummated at the latest on October 22, 2007, when the IMA with AB was signed," Chen wrote.

The ruling resolves the plaintiffs' claims against all defendants except potentially two: Pete Figueiredo and Steve Ingersoll. Chen ordered the parties "to meet and confer and file a status conference statement by Aug. 11, 2016, as to whether there are still any claims against Mr. Figueiredo and Mr. Ingersoll, or whether the Court's analysis in this order is equally applicable to them."

Figueiredo and Ingersoll are "union-side trustees," as opposed to "management-side trustees."